fix htmlSafe import

Author: mansona

addon/services/progress.js

@@ -1,5 +1,5 @@
 import Service, { inject as service } from '@ember/service';
-import { htmlSafe } from '@ember/string';
+import { htmlSafe } from '@ember/template';
 import { tracked } from '@glimmer/tracking';
 import { action } from '@ember/object';